A Claude Code skill is a Markdown document that the assistant loads when a task matches its description. A collection of skills, agents, and hooks can be packaged as a plugin and distributed through a marketplace. Since the summer of 2026, my development environment has relied on such a plugin for Java work, consisting of a set of Spring Boot, Quarkus, Apache Camel, and Jakarta EE agents and skills. This collection started as a small set of artifacts but, little by little, I extended it such that, after several months, it contained 43 files and 17,338 lines.This raised a precise question: were the stack conventions provided by this plugin really contributing anything measurable to the final outcome, or could the model, by its intrinsic general knowledge, infer the same result with much fewer tokens?